This invention relates to a method and apparatus for determining whether a container fluid is leaking. More particularly, it relates to a method and apparatus for determining at an early stage the leakage of minute sodium from a sodium container, for example, cooling pipe in a sodium-cooled fast breeder.
Heretofore, in a sodium-cooled fast breeder, e.g. leakage detection apparatus as disclosed in Japanese Utility Model Publication No. 45254 published in 1977, has been employed in order to prevent a large quantity of sodium from leaking from a cooling pipe. In this apparatus, two electrodes are disposed between the sodium pipe and a heat insulating pipe outside the former pipe, and the situation of short-circuit between the electrodes is monitored with a resistance meter, whereby the presence of the leakage of sodium is detected. Accordingly, there are the following disadvantages. (1) The leakage is decided in reliance on a conduction or non-conduction signal between the two electrodes alone, so that when a place of the leakage is distant from the mounting positions of the electrodes, it will not be detected unless a large amount of sodium leaks. That is, the apparatus is incapable of finding the leakage at an early stage and it is feared to incur a serious leakage accident. (2) The sodium that has once short-circuited the electrodes does not separate from the electrode portion, and sometimes solidifies as it adheres to the electrodes. Therefore, once the apparatus has operated, it cannot restore the performance as a detector. Accordingly, the apparatus cannot continuously detect sodium which is continuously leaking.